Ice making method and machine with PETD harvest

Abstract

An ice making has an ice making mold with a plurality of ice making cells opened at the bottom, a water tank, water spray nozzles adapted for spraying the water contained in the water tank towards the ice making cells, an ice bin adapted for storage of ice cubes formed in and harvested from the ice making cells, and an inclined plate having water spray openings and recovery openings and mounted between the ice making mold and the water spray nozzles. The ice making cells are each attached to a serpentine evaporator tube, which is cooled by a refrigeration system and also heated by way of electrical pulse energy. The electrical pulse heating of the ice making cells allows ice to be quickly and efficiently harvested from the cells.

1. An ice making machine comprising:
 an evaporator assembly comprising an array of ice forming surfaces; 
 a water supply, a refrigerant supply and an electrical energy source; and 
 a controller that during a freeze mode operates said water supply and said refrigerant supply to form ice on said ice forming surfaces and during a harvest mode operates said electrical energy source to apply electrical pulse energy to said evaporator assembly to melt an interfacial layer of said ice such that it is freed from said surfaces, wherein said electrical pulse energy produces a pulsed current flow in said evaporator assembly and heat that melts said interfacial layer. 
 
   
   
     2. The ice making machine of  claim 1 , wherein said evaporator assembly comprises an ice mold that comprises at least one of said ice forming surfaces, and wherein said electrical pulse energy is applied to a member of the group consisting of:
 said ice mold and an electrically conductive element that is in thermal transfer relation to said ice mold. 
 
   
   
     3. The ice making machine of  claim 2 , wherein said evaporator assembly further comprises an evaporator tube, and wherein said electrically conductive element comprises said evaporator tube. 
   
   
     4. The ice making machine of  claim 3 , wherein said electrical energy source is connected in circuit with a segment of said evaporator tube. 
   
   
     5. The ice making machine of  claim 4 , wherein said segment is between a midpoint and an end point of said evaporator tube. 
   
   
     6. The ice making machine of  claim 5 , wherein said electrical energy source is further connected in circuit with said midpoint and an opposite end point of said evaporator tube. 
   
   
     7. The ice making machine of  claim 6 , wherein said end points are connected to a circuit reference. 
   
   
     8. The ice making machine of  claim 2 , wherein said electrically conductive element comprises an electrically conductive ice mold. 
   
   
     9. The ice making machine of  claim 2 , wherein said ice mold is selected from the group consisting of: cups and fingers. 
   
   
     10. A method of making ice with an ice making machine that comprises an evaporator assembly comprising an array of ice forming surfaces, a water supply, a refrigerant supply and an electrical energy source, said method comprising:
 during a freeze mode operating said water supply and said refrigerant supply to form ice on said ice forming surfaces; and 
 during a harvest mode operating said electrical energy source to apply electrical pulse energy to said evaporator assembly to melt an interfacial layer of said ice such that it is freed from said surfaces, wherein said electrical pulse energy produces a pulsed current flow in said evaporator assembly and heat that melts said interfacial layer. 
 
   
   
     11. The method of  claim 10 , wherein said evaporator assembly comprises a ice mold that comprises at least one of said ice forming surfaces, and wherein said electrical pulse energy is applied to a member of the group consisting of: said ice mold and an electrically conductive element that is in thermal transfer relation to said ice mold. 
   
   
     12. The method of  claim 11 , wherein said evaporator assembly further comprises an evaporator tube, and wherein said electrically conductive element comprises said evaporator tube. 
   
   
     13. The method of  claim 11 , wherein said electrically conductive element comprises an electrically conductive ice mold. 
   
   
     14. The method of  claim 11 , wherein said ice mold is selected from the group consisting of: cups and fingers. 
   
   
     15. The ice making machine of  claim 1 , wherein said electrical pulse energy is Pulse Electro Thermal Deicing (PETD) energy. 
   
   
     16. The ice making machine of  claim 10 , wherein said electrical pulse energy is Pulse Electro Thermal Deicing (PETD) energy.